Lasers have been utilized for aiming firearms by mounting a laser unit on the firearm sights or within firearms (U.S. Pat. No. 5,237,773). Many of these laser units have operating switches located upon the laser unit, or are located upon the grip or other areas of the firearm and are connected to the laser unit by wires. None, however, combine an integrally frame-mounted laser unit with a reversible cross-mounted push button operating switch located in the frame immediately in front of the trigger operating area, for both security and ease of operation.